Typewriting machine



March 9, 1937. W, F HELMOND 2,072,878

TYPEWRITING MACHINE Filed Feb. 23, 1935 5 Sheets-Sheet l BY my z.

' ATTORN v March .9, 1937. w. F. HELMOND 2,072,878

TYPEWR'ITING MACHINE Filed Feb. 25, 1935 5 sheets-sheet 2 l March 9,1931. W. F. HELMOND 2,072,878

TYPEWRIT'ING MACHINE Filed Feb. 23, 1955 5 Sheets-Sheet 3` NVENTOR:

March 9, i937, w. F. HELMOND TYPEWRITING MACHINE Filed Feb. 25, 1955" 5Sheets-Sheet 4 wdr.

INVENTOR:

l BY ATTORN March 9, 1937. w. F. HELMOND TYPEWRITING MACHINE Filed Feb.l25, 1955 INVENTOR:

ATT NEY.

Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE TYPEWRITING MACHINEApplication February 23, 1935, Serial No. 7,679

10 Claims.

This invention relates to typewritery typeactions and will be hereinexplained with referlence to a system of pivoted front-strike type-barsnormally cumbent in an arcuate array which curves upwardly from themiddle towards the sides of the system, and an associate system oftype-key-levers extending individually fore and aft of the machine anddisposed in substantially horizontal array below the type-bars.

The horizontal array of key-levers is to be connected to the arcuatearray of type-bars by a system of type-bar-accelerating connections, sothat there will ybe ease of key-touch at the beginning of the key-leverstroke, hand-cushioning absorption of the momentum of the operators handat the end of the key-lever-printing stroke, and sharp printing impactof the type for clear printing and manifolding.

To these primary ends, said connections include a system of upstandingsub-levers. From a common fulcrum-axis the sub-levers range, in varyingdegree, upwardly and inwardly for,` disposing their upper end-portionsin conformity with the arcuate array of cumbent type-bars to which saidupper end-portions are connected, the lower portions of the sub-leversbeing contiguous to their respective key-'levers for connection to thelatter, at a zone which is between the key-lever fulcrums and keys.

Each sub-lever is connected, at a point between its fulcrum-end andupper type-bar-driving end, to its key-lever by a short link extendingforwardly from the sub-lever to an opposite point provided upon thekey-lever. The arrangement 3;, is such that, during the dip of thekey-lever, said short link pulls upon the sub-lever in a direction whichbecomes increasingly inclined toward a line joining said sub-lever pointand fulcrum. The sub-lever and type-bar accordingly start 40 slowly, tomake the key-touch easy, at the beginning of the key-stroke, thesub-lever and typebar speed continuously increasing as the keystrokeprogresses at uniform speed, there being,

correspondingly, continuously increasing resistance at the keythroughout said stroke, thereby 55 type-bar-driving ends of thesub-levers, it being understood that the throws of the several links areto be substantially alike.

According to the invention, there is taken a novel link-pivot locus,with reference to which said links are established at their gradedelevations, an'd the use of such novel locus affords importantadvantages.

To this end, a common key-lever fulcrum-axis and a locus for the pointsat which the links are pivoted to the sub-levers are relatively disposedso as to conduce to equi-distance of said linkpivotv points from saidkey-lever fulcrum-axis. For exactequidistance, said locus may be in theform of a circular arc whose center is said keylever fulcrum-axis. Theradius of such curved locus may be such that a straight line passingthrough the highest and lowest pivot-link points on the sub-levers wouldbe directed toward the sub-lever fulcrum-axis.

A further feature of the invention resides in applying such a locus to amachine in which the common key-lever fulcrum-axis is in theconventional location-near the base of the machine, as, for example, inthe standard Underwood typewriter. The common sub-lever fulcrum may alsobe near said machine-base. In such case, it is feasible to provide thenovel locus for the substantially higher link-pivot points on thekeylevers by pitching said locus to slant rearwardly.

The links extend forwardly from the novel locus for pivotal connectionto companion points on the key-levers. The links may be uniform inlength throughout the type-action system; or, as will hereinafterappear, they need vary but slightly in length, to thereby provide foruniform depths of key-strokes where the lengths of the key-levers, fromfulcrum to key, vary, as in a machine having a four-row keyboard fromwhich the key-levers extend to the common fulcrumaxis, there being insuch machine only four gradations of link-lengths.

Since, by use/of the novel locus, the link-pivot points, onthe/sub-levers, are equidistant from the mean or common key-leverfulcrum-axis, and the forwardly-extending links are substantiallyuniform in length, it follows that the lengths of the lines from thekey-lever fulcrums to the linkpivot points on the key-levers may besubstantially uniform throughout the system, it being furthermorearranged that the angular relations of said links to said lines besubstantially uniform throughout the system with reference to the normalpositions of the parts.

Thus, by having said lines, which constitute the link-actuatinglever-arms of the key-levers,

j may be made substantially uniform for all keysf.

substantially uniformV throughout the system, and at the same timehaving said angular relations to said lines substantially uniform, itwill be found that the reactions upon the type-bars, by means of thelinks and graded sub-levers, may be made substantially uniformthroughout the system, to the end that the keys may have uniform ease ofkey-touch throughout the keyboard at the beginningof any key-stroke.

It will also be found, by use of the novel locus, that the nalinclination of any link to the linkarm of the sub-lever, at the end ofthe key-stroke,

throughout the system, and that thereby, and also by reason of theaforesaid link-actuating lever-arms of the key-levers beingsubstantially uniform, the reaction upon the type-bars by means of thesub-levers and links at the instant of high-speed-printing impact may besubstantially uniform throughout the system. It will further be found,with reference to any intermediate phase of any key-stroke, that theratio of type-bar speed to key speed will be substantially the same forall keys, and that consequently, irrespective of whether a type-bar atthe middle or at either side of the system is operated, thecorresponding keys will start the type-trains with uniform ease ofinitial key-touch, and there will be uniformity in the continuousincrease of the speed of any type-bar, and consequent uniformmomentum-absorbing hand-cushioning at the keys, at the instants ofprinting impacts.

The laforementioned pitching of the locus for the link-pivots does notrnilitate against the use of uniform means such as uniform pull-rods forconnecting the sub-levers and type-bars. The use of such pull-rods whichextend rearwardly from the sub-levers to the type-bars makes it feasibleto dispose the system of sub-levers, the novel link-pivot locus and thelinks well forward of the type-bar system, and therefore well forwardfrom the key-lever fulcrums, to thereby gain the advantage of workingwith an adequately extended stroke at the link-pivot on the key-lever,and other advantages. l

The invention also provides improvements pertaining to a system ofretracting springs associated with the novel type-actions. Therearefernployed a set of key-lever springs, and a set of auxiliary springsto aid the key-lever springs as when the purchase of a key-lever uponthe sublever at the beginning of its return stroke is at a minimum, dueto the maximumv inclination at that time of the connecting link. Theauxiliary springs are therefore arranged to act directly upon thesub-levers and extend from a common anchor-member. The key-lever springsextend from a separate, common anchor-member, and novelwmeans areprovided whereby said anchormembers may be jointly or individuallyadjusted to effect joint or individual adjustment of the tension effectsof the two sets of springs, the arrangement-furthermore being such thatindividual adjustment of the several key-lever springs may be effected.

Improved devices are also provided whereby the connection ordisconnection of the sub-levers, links and key-levers, as in servicingtheumachine, is facilitated.

Other yfeatures and advantages will hereinafter appear.

In the accompany drawings,

Figure lI is a side-elevation View of the novelV type-action andspring-system, and parts of the typewriter related thereto, some of themembers being shown in section.

Figure 2 is an enlarged fragmentary plan view, showing details of thearrangement provided to facilitate connection and disconnection of thesub-lever, key-lever and connecting link.

Figure 3 is a perspective View, showing features of the type-action andspring-system in detail, some of the parts being sectioned and brokenaway for clearness.

Figure 4 is a frontlview of the sub-levers to illustrate the grading ofthe upper ends of the latter for connection to the type-bars.

Figure 5 is a side-elevation view, showing a middle type-action of thesystem operated to printing-position.

Figure 6 is a fragmentary elevation view to illustrate tilting of thetype-bar segment to provide clearance between the array of type-bars andparts thereunder.

Figures '7, 8, 9 and 10 are straight-line diagrams of the type-actions,Figures 7 and 8 showing respectively normal and operated positions oftypeaotions corresponding to the rearmost bank or row of type-keys,while Figures 9 and 1.0 show normal and operated positions of thetype-actions corresponding to the foremost bank of type-keys'. Figure 11is a view illustrative of four gradations of the links connecting thesub-levers and keylevers.

Key-levers I5 having type-keys I6, constituting the usual keyboard,extend rearwardly from the latter to a common fulcrum-rod Il retained ina cross-bar I8, supported by the partly-shown main frame I9 of themachine. Slots 20 of said crossbar space the rear ends of the key-leverstransversely of the machine. A comb-plate 2l, supported bythemachine-framework, similarly spaces the key-levers at their forwardportions,

and may support a cushioning stop 22 Awhich the key-levers abut, Figure1, to determine their normal positions.

By means of said key-levers, and novel connections which will presentlybe described, typebars 23, normally cumbent in arcuate array, asindicated in Figures 1 and 3, are selectively actuated to bring theirtypes 24 to a common printingpoint traversed by a platen 25 mounted in acarriage (not shown).

A type-bar segment 21, having an arcuate fulcrum-rod 28, about which thetype-bars 23 swing, and also having radial type-bar-spacing slots 29,determines the arcuate type-bar array which curves upwardly from themiddle to the sides of the system, and in which array the cumbenttype-bars abut an arcuate rest 30. A type-guide 3| upon the segment 21co-operates in known manner with a nose 32 of any type-bar to gage theprinting-point.

'I'he key-levers I5 have their fulcrum-rod I1, at the rear of themachine, somewhat above the base of the machine, as indicated in Figure1, and are disposed in horizontal array acrossthe machine.

In the means for connecting the horizontallyarrayed key-levers to thearcuately-arrayed typebars, there is included a system of gradedsublevers 34 upstanding from a common fulcrumrod 35, disposed somewhatabove the base of the machine, Figure 1, and horizontally retained in across-bar 36, which may be supported by the main frame I9. Saidcross-bar has slots 31, whereby the lower portions of the sub-levers arelevers I5, the latter being formed with uniform ating arms 53a of thetype-bars by pull-rods li,

the array of sub-levers 3A being disposed forwardly of the type-barfulcrum-rod 2B. For uniformity in the lengths of said pull-rods 4d, saidoperating points 43 of the type-bars may be uniformly disposedrelatively to the fulcrum-rod 26, and the sub-levers may be formed sothat their upper type-bar-driving points t2 are uniformly disposedrelatively to said type-bar-operating arms, as indicated in Figure 1.

In order that the key-touch may be light at the beginning of thekey-stroke, and that the speed of the sub-lever 313 and type-bar 23continuously increases from a slow starting speed while the key-strokeprogresses at even speed, each keylever I5 is connected to thecorresponding sublever 3d by .a link 135. The arrangement is such thatsaid link l5 becomes increasingly inclined to the sub-lever 33, andthereby increases the ratio of movement of the latter to the key-levermovement, as the key-stroke progresses, as may be understood from acomparison of Figures 1 and 5, which respectively show a type-action innormal position and operated to printing-position.

For such action, each link l5 is pivotally connected to its sub-lever 36at a point d6, intermediate of the type-bar-driving point d2 and thefulcrum-rod 35, and the link extends forwardly from the sub-lever, as inFigure 1, for pivotal connection to a companion point il on thecorresponding key-lever I5. The lower portions of the sub-levers, whichinclude the link-pivots d5, may be disposed in conformity with the arrayof key-levers. For conforming to the narrower, arcuate array of thepoints i3 on the type-bars, the upper end-portions of the sub-levers,which include the type-bar-driving points d2, are made to converge, bybending them inwardly, as indicated at 38, Figure 3, it being understoodthat, from the middle of the system, where the sublevers 3Q arepractically straight, the heights of the bends at d8 and the inwardinclinations of the upper sub-lever portions i9 may be graded asindicated in Figure 4.

The links i5 -work at graded elevations or distances above the sub-leverfulcrum-rod 35, in order that substantially uniform throws of said linksas effected by the key-lever strokes may produce substantially uniformstrokes at the type-bar-driving points 42 of the graded sublevers 34.Thus, the link-pivot points 46 on the several graded sub-levers are atgraded distances or elevations above the sub-lever fulcrum-rod 35, and,conformingly, the companion link-pivot points lil on the severalkey-levers I5 are disposed at graded elevations by means ofpointprojecting arms 5I of graded lengths formed on the severalkey-levers at the corners of the keylever portions 39 and 40.

A locus 52 for the link-pivot points 46 on the sub-levers 3B of theseveral type-actions viewed as in Figure 1 is disposed relatively to thecommon key-lever fulcrum-axis II, so as to conduce to equidistance ofsaid points 46 from said axis II. To this end, where said key-leverfulcrum-r` axis I1 and the sub-lever fulcrum-axis 35 are near the baseof the machine, as indicated, and said link-pivot points 46 aresubstantially higher, said locus may be pitched or slanted rearwardly.

For exact equidistance of the sub-lever-linkpivot points 46 from thekey-lever fulcrum-axis I'I, said locus 52 may be in the form of acircular arc, whose center is at the key-lever fulcrum-axis I1, andwhose radius R, Figures '7 and 9, is preferably such that a straightline through the highest and lowest sub-lever-link-pivot points 46 onsaidA circular locus is directed toward the sub-lever fulcrum-axis 35.

The links 65 may be uniform in length, or, as will presently beexplained, they may vary slightly in accordance with the rows of keys I6of the keyboard. Thus the lengths of the linklever arms from fulcrum I1to link-pivot point i1 on the key-levers will be practically uniformthroughout the system, it being noted that, in conjunction with thisuniformity of said linklever arms II, 4H, the inclination of the links45 thereto may also be substantially uniform throughout the system. Itwill be found also that the inclinations of the links d5 to the arms 35,d6 of the sub-levers will be substantially uniform at the ends ofthekey-strokes. In the straight-line diagrams at Figures 7 and 9, theuniform link-inclination to the link-lever arms l1, d1, in the normalposition of the parts, is taken at say fifteen degrees, and, asindicated in the diagrams at Figures 8 and 10, the inclination of saidlink to the sub-lever arm 35, 46, at the end of the key-stroke will besubstantially uniform at say twenty-five degrees.

Since the key-lever length from the common fulcrum I'I to key I6 isdifferent for each row of keys, it will be seen that, for uniform depthof key-stroke, the angular displacement of the keylevers for the severalkey-rows will be different.

.Taking the key-levers for the rearmost and foremost rows for comparisonand their respective greater and less angular displacement for equaldepths of key-stroke, it will be found that the Condition of uniformityof the initial and final inclinations of the links i5 may be preservedby making the links i5 for the foremost row of key-levers somewhatshorter than the links d5 for the rearmost row.

The diagrams at Figures 7 and 8 represent, respectively, the normal andoperated positions of the type-actions for the rearmost row of keys; andthe diagrams at Figures 9 and 10 represent, respectively, the normal andoperated positions of the type-actions for the foremost row of keys, thekeys in said rows having the same depths of key-strokes.

Said diagrams at Figures 7-10 indicate the desired uniformity of initiallink inclination of say the given fifteen degrees, and also indicate theuniformity of final link inclination of say the given twenty-fivedegrees, said uniformity being attained by the described difference inlink lengths. It will be understood that the lengths of the links 45 forthe key-actions for the intermediate or illustrated second and thirdrows of keys will be intermediately graded to the end that the initialand nal link inclinations be uniform with those of the foremost andrearmost rows of keys. Thus, for a fourrow keyboard there will be fourgradations of link lengths, as indicated in Figure 11.

Each of the diagrams at Figures 7-10 represents a full row oftype-actions by the showing of lines for a middle type-action and for atypevdotted lines 56, Figure 1.

action at the end of the row, it being deemed unnecessary to indicatethe intermediate type-actions, since it is to be understood that thegradations of the link-pivot points 46, 41, by means of the curved locus52, are between the two eX- tremes illustrated in each diagram. It willalso be understood that the initial and nal link inclinations areuniform for the type-actions in each key-row, as well as with respect tothe typeactions for the several key-rows. It may also be noted that saidgradations of the link-pivot points 46, 41, by means of the locus 52,are arranged to effect uniform throws, represented in said diagrams bythe dotted lines 54, of the type-bar-driving points 42 of the sub-levers34.

It will be seen that, by use of a link-pivot locus, such4 as 52, thereare gained two important advantages, namely, the link-actuating1ever-arm I1, 41 of the key-levers may be substantially uniformthroughout the system, and

the aforementioned initial and final link inclinations may also eac-h besubstantially uniform throughout the system. It will be found to resultfrom said conditions that each type-action has the same characteristicas to touch and printing and lmanifolding effect.

In other words, links such as 45 are used to the best advantage in thatthey are herein so arranged relatively to sub-levers such as 34 andkey-levers such as I5, as to conduce to uniformity throughout thesystem, in the initial ease of keytouch due to the slow starting of thetype-action, and to uniformity in the continuous increase of thetype-bar speed as the key-stroke progresses evenly, said uniformity ofthe continuous increase intype-bar (and sub-lever) speed conducing touniformity in the increased resistance at the key, and thereby conducingto uniformity in cushioning the operators hand at the instant ofprinting impact of the types. The uniformity of continuous increase oftype-bar speed also has the effect of conducing toI uniformly sharpimpact of the type-bar at the instant of printing, to make the printinguniformly clear and conduce to uniform good manifolding by anytype-action irrespective of whether it is at the middle or the side ofthe system.

In Figure 1 the dotted lines 55 represent equal increments of thekey-stroke. Said equal keystroke increments produce, by means of theaccompanying increase in the inclination of the link 45, continuouslyincreasing increments in the type-bar displacement as represented by theThus, the type-bar starts slowly with the first increment of thekeystroke and following equal increments of the keystroke each producean increased type-bar displacement as represented by the increasingspaces between the dotted lines 56, each of which corresponds to a line55 at the key I6 as indicated by the numerals 0 to 9 at said dottedlines 55, 56.

The final increment 8, 9 at the lines 56, representing the type-barmovement, indicates that the type-bar speed will have been acceleratedto a maximum at the instant of printing, so that there will be sharpprinting impact of the type conducive to clear printing and'manifolding.

It is to be noted that the proportions of typebar displacement to equalincrements of the keystroke, as' depicted in Figure 1, obtainsubstantialy uniformly throughout -the system by reason of theherein-described arrangement of the keylevers I5, the sub-levers 34 andthe links 45,

g5 thereby conducing to the described uniformity in key-touch andprinting-characteristics of the type-actions throughout the system.

'I'he novel spring-system for they type-actions will now be described.

For each key-lever I5 there is an individual restoring spring 58, whichby means of notches 59 upon the key-lever may engage the latter atdifferent distances from the key-lever fulcrumrod I 1, to therebyregulate the effect of the spring upon'the key-lever. The springs forthe several key-levers are connected to a common anchorrod 68, supportedat its ends by arms 6I and at an intermediate point by an arm v62, saidarms 6I, 62 extending forwardly from and being fastened to a cross-rod63, removably journaled at its ends in open sockets 64 formed in themain frame I9, as indicated in Figure 3. An arm 65 extending from themain frame I9 is arranged as shown to support the cross-rod 63, at apoint intermediate its ends to minimize defiection of said cross-rod 63and anchor-rod 60 under the pull of the row of springs 58.

Extending rearwardly from and fastened to the cross-rod 63 is an arm 66having notches 61, in one or another of which a link 68 pendent fromsaid notched arm 66 is caught, said pendent link 68 being similarlycaught at its lower end in one or another of notches formed by thethreads of a screw 69, which projects forwardlly from the main frame I9and co-operates with said pendent link 68 for adjustably securing thespring-anchor structure comprising the rods 60, 63. Said screw 69 may beguided for endwise adjustment in a bushing 10 and carries a thumb-nut 1Ifor effecting said adjustment micrometrically. For articulation with thenotches 61 of arm 66 and of the screw 69, the pendent link 68 may havesharp-edged openings 12, as indicated in Figures 1 and 3.

By means of a flattened forward extension 14 slidably tting a guide-slot15 in a cross-bar 16, supported at the sides of the main frame I9 towhich it may be secured by screws 16a, the screw 69 is prevented fromturning so that turning of the thumb-nut 1I is effective to move thescrew 69 endwise in a forward or rearward direction. Said cross-bar 16also co-operates to support the screw 69 against deection under. thepull of the pendent link 68. Such endwise movement of the screw 69shifts the bottom of the link 68 forwardly or backwardly, and therebycauses turning of the spring-anchor frame in the sockets 64 to therebyraise or lower the anchor-rod'60 to vary the tension of all thekey-lever springs 58. Thus, by turning said thumb-screw 1I one way orthe other, the tension effect of the springs 58 upon all the key-leversis varied, while, for individual adjustment of the tension effect uponeach keylever, the lower end of the corresponding spring gg may beadjusted along the key-lever notches Referring to Figure-5, which showsa typeaction in printing-position and about to commence its returnstroke, it will be seen that the effect of the key-lever spring 58 is ata minimum for starting the return of the type-action, in so far as thepurchase of the key-lever upon the sub-lever 34 is at a minimum due tothe maximum inclination of the link 45. For reinforcing the effect ofthe key-lever springs 58 at the start of returning the type-action,there is provided a system of auxiliary springs 11, arranged to actdirectly upon the sub-levers 34. Each auxiliary spring 11 mayaccordingly be attached at one end lower the spring-anchor rod 60.

to a stud 46 which, as indicated in Figures 1, 3 and 5, also serves asthe link-pivot 46 upon the sub-lever. The other ends of the set ofauxiliary springs 11 may be attached to a' common anchorplate 19, which,for adjustment to vary the tension of all the auxiliary springs 11, maybe connected to the screw 69, the flattened portion 14 of the latterhaving for this purpose a hooked end 80 engaging a companion slot 8| insaid auxiliary spring-anchor plate 19.

It will be seen that a quick change or adjustment of the tension eiect.of the key-lever springs 58 may be made by pressing downward at theupper end 68al of the link 68 to free its lower end from the screw 59,and then tilting said link forward or backward to change the location ofsaid lower link-end along the screw 69, to raise or In this way quickand say approximately correct adjustment of the tension eect of thekey-lever springs 58 may be made first, and then the thumb-nut 1| may beturned to make a liner adjustment of the tension effect of the key-leversprings 58. It will also be seen that, by turning the thumbnut 1|, thetension effect of the key-lever springs 58 and the sub-lever auxiliarysprings 11 may be adjusted` jointly, provided the link 68 remains inengagement with the screw 69. The sublever or auxiliary springs 11 mayalso be adjusted without changing the tension effect of the key-leversprings 58. In such case the thumb-nut 1| would be turned until thedesired tension effect of the auxiliary springs 11 is obtained, the link|58 being manipulated either to restore the lower link-end, after thethumb-nut 1| is turned for the auxiliary spring adjustment, or to holdsaid lower link-end clear of the screw 69, while the thumb-nut 1| isturned to effect the auxiliary spring adjustment.

It will also be seen that movement of the lower end of the link 68 alongthe screw 69 will cause raising or lowering of the key-leverspring-anchor rod $9 to extents which will vary in accordance with theparticular notch 61 of arm 66 which the link 68 depends from.

For facilitating connection and disconnection of the links 45, thesub-levers 34 and the keylevers i5, the studs. which constitute thelinkpivot points 46 and 41 and which have the same reference numbers assaid pivot-points, may be made Without enlarged heads, and, in lieu ofsaid enlarged heads, said studs m/ay extend substantially beyond theouter side of the link, as indicated in Figure 2. Adjacentdy said outerlink-side the link-pivot stud 46 may have a groove 82 into which anelongately loopedfnd 83of the auxiliary or sub-lever spring 11 is hookedto keep the link 45 in place. Thus, when y, e auxiliary spring-end sa isunhcoked from th/pivot-stud 4s, the 1mi: 45 may be readily disconnectedfrom or reconnected to the sub-lever and key-lever to facilitateservicing of the machine. With the links 45 disconnectible andreconnectible as described removal and replacement of any key-lever l isfacilitated, it being noted that to this end the key-lever reach 39, 40,4|', from the keyboard to the key-lever fulcrum-rod |1 is arranged topass under the array of sub-levers 34 and other parts. The verticalportions 40 of the key-lever reaches may present shoulders 84 engageableby a keylocking device not shown.

It will be noted that, by using the pull-rods 44 to connect thetype-bars 23 and sub-levers 34, the latter are disposed well forward inthe machine, so that, correspondingly, the links 45 are easilyaccessible for removal or replacement.

There is also gained by such forward disposal of the sub-levers adequateextent of stroke at the link-pivot point 41 on the key-levers.

The type-bar segment 21 may be guided for case-shifting movementseifected by suitable means represented by bell-cranks 85, in Figures 1and 3, there being one of said bell-cranks at each side of the segment,and the bell-cranks being. connected to shift the segment parallelly.'As indicated in Figure 3 there may be at each side of the segment 21,for guiding the latter, a raceway 86 on the machine-framework I9, acompanion raceway 81 on the segment and an antifriction roller 88. Whenthe type-bars -23 are shifted with their segment 21 down or up, thepull-rods 44 move idly about the points 42 on the sub-levers. Thetype-bar rest 30 shifts with the type-bar segment 21, a support 89 forsaid rest 39 being connected to the type-bar segment 21 by rods 89a.

Figure 6 shows a type-bar segment 21a tilted so that the array oftype-bars 23 is correspondingly tilted to afford adequate clearancebetween the type-bar array and the sub-levers 34, as when the type-bararr-ay is depressed to the lowercase position indicated by the dottedoutline in Figure 6.

Each type-bar 23 may have near its fulcrum a heel 9U to actuate anarcuate universal bar 9|. Connected to said universal bar are side-arms92 pivoted to a rock-frame 93, journaled at 94 in arms 95 extendingrearwardly from the type-bar segment 21. Said rock-frame 93 co-operateswith a tongue 96 of the universal-bar structure to support the latterfor fore-and-aft movement, said tongue being slidably tted in thetype-bar segment 21. Mechanism such, for example, as a letter-feedingescapement to be actuated by the universal bar 9| may be stationary withrespect to the case-shiftable type-bar segment 21, and isdiagrammatically indicated at 91, Figure 1. A link 98 may extend fromthe universal-bar structure on the type-bar segment and swings idlyabout the point 99 of said mechanism 91 at the case-shift movements ofthe type-bar segment.

Variations may be resorted to within the scope of the invention andportions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a system of-key-operated trains for actuating a set of typewritertype-bars; a series of type-key levers extending from a keyboard to amean fulcrum-axis, a series of upstanding graded sub-levers connected tothe type-bars, said sublevers arrayed transversely of the machine at aZone between the keyboard and the key-lever fulcrum-axis, and a seriesof links connecting the key-levers and sub-levers at graded elevations,said links being arranged 'so that each link becomes inceasinglyinclined to its sub-lever as the key-lever printing-stroke progresses',to thereby accelerate said sub-lever and its type-bar, the acceleratinglinks being further arranged with their pivotal connecting points, tothe sub-levers and to the key-levers, respectively, at substantiallyequal distances from said mean key-lever fulcrum-axis, thereby toconduce to uniformity in the acceleration of the several sub-levers andtype-bars.

2. In a system of key-operated trains for actu-- levers arrayedtransversely of the machine at a zone between the keyboard and thekey-lever fulcrum-axis, and a series of links connecting the key-leversand sub-levers at graded elevations, said links being arranged sov thateach link becomes increasingly inclined to its sub-lever as thekey-lever printing-stroke progresses, to thereby accelerate saidsub-lever and its type-bar, the accelerating links being furtherarranged with their pivotal connecting points, to the sub-levers and tothe key-levers respectively, at substantially equal distances from saidmean key-lever fulcrum-axis, and arranged also so that the initial andnal inclinations of each link to its sublever are substantially uniformwith reference to the several sub-levers, thereby to conduce touniformity in the acceleration of the several sublevers and type-bars.

3. In a system of key-operated trains for actuating a set of typewritertype-bars; a series of type-key levers extending from a keyboard to amean fulcrum-axis, a series of upstanding graded sub-levers connected tothe type-bars, said sublevers arrayed transversely of the machine at azone between the keyboard and the key-lever fulcrum-axis, and a seriesof links connecting the key-levers and sub-levers at graded elevations,said links being arranged so that each link becomes increasinglyinclined to its sub-lever as the key-lever printing-stroke progresses,to thereby accelerate said sub-lever and its type-bar, said acceleratinglinks at their graded elevations, and in the normal positions of saidtrains, having their points of pivotal connection to the sub-levers on acurved locus which is concentric with the mean key-lever fulcrum-axis,thereby to conduce to uniformity in the acceleration of the severalsublevers and type-bars. l'

4. Inra system of key-operated trains for actu ating a set of typewritertype-bars; a series of type-key levers extending from a keyboard to amean fulcrum-axis, a seriesof upstanding graded sub-levers connected tothe type-bars, said sublevers arrayed transversely of the machine at azone between the keyboard and the key-lever fulcrum-axis, and a seriesof links connecting the key-levers and sub-levers at graded elevations,said links being arranged so that each link becomes increasinglyinclined to its sub-lever as the key-lever printing-stroke progresses,to thereby accelerate said sub-lever and its type-bar, said acceleratinglinks at their graded elevations, and

in the normal positions of said trains, havingv ating a set oftypewriter type-bars; a series of type-key levers extending from akeyboard to a mean fulcrum-axis, a series of upstanding gradedsub-levers connected to the type-bars, said sub- ,levers arrayedtransversely of the machine at a zone between the keyboard and thekey-lever fulcrum-axis, and a series of links connecting the key-leversand sub-levers at graded eleva-tions, said links being arranged so thateach link becomes increasingly inclined to its sub-lever as thekey-lever printing-stroke progresses, to thereby accelerate saidsub-leverand its type-bar, said accelerating links at their gradedelevations, and

in the normal positions of said trains, having their points of pivotalconnection to the sub-levers on a curved locus which is concentric withthe mean key-lever fulcrum-axis, thereby to conduce to uniformity in theacceleration of the several sublevers and type-bars, said key-leversbeing of different lengths to form the key-rows of the keyboard, and thelengths of said links being graded in correspondence with the severalkey-rows, whereby the operation of said sub-levers and type-bars iseiected by key-strokes which are substantially uniform in depththroughout the keyboard.

6. In a system of key-operated trains for actuating a set of typewritertype-bars; a series of type-key levers extending from a keyboard to amean fulcrum-axis, a series ofl upstanding graded sub-levers connectedto the type-bars, said sub-levers arrayed transversly of the machineat azone between the keyboard and the key-lever fulcrum-axis, and a seriesof links connecting the key-levers and sub-levers at graded elevations,said links being arranged so that each link becomes increasinglyinclined to its sublever as the key-lever printing-stroke progresses, tothereby accelerate said sub-lever and its typebar, said acceleratinglinks at their graded elevations, and in the normal positions of saidtrains,

having their points of pivotal connection to the sub-levers on Ia curvedlocus which is concentric with the mean key-lever fulcrum-axis, and saidaccelerating links, in said normal positions of the trains, extendingseverally at substantially uniform angles from said locus, thereby toconduce to uniformity in the acceleration of the several sub-levers andtype-bars, said key-levers being of diierent lengths to form thekey-rows of the keyboard, and the lengths of said links being graded incorrespondence with the several keyrows', whereby the operation of saidsub-levers and type-bars is effected by key-strokes which aresusbtantially uniform in depth throughout the keyboard.

7. In a system of key-operated trains for actuating a set of typewritertype-bars, the typewriter having a box-like frame; a series of typekeylevers extending rearwardly from a keyboard at the front of said frameto a mean fulcrum-axis disposed near the rear bottom corner of saidframe, a series of sub-levers upstanding in graded extents from theirfulcrums and connected by means of their upper ends to the typebars,said gub-levers being arrayed transversely of the machine at a zonebetween the keyboard and the key-lever fulcrum-axis, and a series oflinks connecting the key-levers and sub-levers at graded elevations inaccordance with the diierent extents of the sub-levers, said links beingarranged so that each link becomes increasingly inclined to itssub-lever as the key-lever printing progresses, to thereby continuouslyaccelerate said sub-lever and its type-bar, said accelerating links, attheir graded elevations and in the normal positions of said trains,having their points of pivotal connection to the Sub-levers on a locuswhich is inclined upwardly and rearwardly to conduce to equidistance ofsaid points from said mean key-lever fulcrum-axis, thereby to conduce touniformity in the acceleration of the several sub-levers and type-bars.

8. In a front-strike typewriting-machine typeaction system, a set oftype-key levers disposed in horizontal array across the machine, andextending individually fore and aft of the machine and from a meanfulcrum-axis, an arcuate array lof-"normally cumbent pivoted type-bars g`'above the'key-levers, a system of sub-levers up- Am Y standing ingraded lengths from their fulcrums andfdisposed at a zone between saidkey-lever fulcrum-axis and the keyboard, said sub-levers being..connected at their upper ends to said k type-bars, and a system of.links connecting the uniform'strokes of the links. as eiected by thekey-levers', eiect substantially uniform strokes of-the upper type-baractuating ends of the suble'vers, the sub-levers and key-levers beingrelaf `tively arranged, so that the locus of the points of Alink-connection on the sub-levers is such that vsaid points aresubstantially equidistant from: said mean key-lever fulcrurn-axis,thereby- -to conduce vto uniformity'of s'aidtype-bar accelera-` tionthroughout thesystem. i

9, Ajsystem of front-strike type-actions including'v swingable type-barscumbently arrayed around a fulcrum-axis curving upwardly to the left andright of the middle, a set of type-key levers below said type-bars andextending rearwardlyl from a keyboard to a mean fulcrum-axis, and asimple system of connections devised to enable said key-levers toactuate said type-bars uniformly as to key-touch, acceleration of thetype-bar printing stroke, and printing impact, said system ofconnections including sub-levers of the third class upstanding from atransverse common fulcrum-axis, said sub-levers being connected at theirupper ends to said type-bars, and being therefore graded as to thelength of their type-bar-actuating arms,` and 'links severallyconnecting the key-levers and sub-'levers at elevations gradedproportionately to said type-baractuating arms, said links beingarranged so that each link becomes increasingly inclined to itssub-lever'as the key-lever printing stroke pro- -gresses foraccelerating said sub-lever and its type-bar, said links, in the normalpositions of the type-actions, having their graded points of pivotalconnection to the sub-levers on such f locus as to be substantiallyequidistant *from the mean key-leVer-fulcrum axis,

l0. In a system of front-strike type-actions, swingable type-barsnormally cumbent at the middle, sides and intermediate places of anarcuate array of the character described, key-levers below said type-bararray and extending rearwardly from a keyboard to a mean fulcrum-axis,sub-'levers having ulcrum-means between the key-lever-fulcrum axis andkeyboard, said sublevers iembodying type-bar-actuating arms graded indiierent lengths in conformity with the arcuate type-bar array, saidsub-levers also embodying operating arms defined by points graded, as

4to distance from the sub-lever-fulcrum means,

proportionately to the type-bar arms, and linkvrods, ealch connecting asub-lever operating point v vto a companion point of the key-lever, eachlinkrodbeing arranged so as to become increasingly inclined to itssub-lever as the key-lever printing stroke progresses for continuouslyaccelerating said sub-lever and type-bar, the graded A tion, whether atthe middle, side or intermediate place of the type-action system, hassubstantially the same characteristics as to key-touch, keystroke,type-bar acceleration, and printing impact.

WILLIAM F. HELMOND.

